It was not quite Agueroooo but it made Pep Guardiola scream.
It was not quite a title clincher but it was significant enough to have the substitutes in uproarious celebration.
And it was a thing of beauty, a symbol of his magnificent decade in a Manchester City shirt.
By their standards, City had been toiling for almost an hour, failing to muster a single shot on target in the first half.
That is like Michael van Gerwen not hitting the dartboard.
But when Benjamin Mendy curled a clever ball into the penalty area, Aguero had taken one touch and dispatched a rocket into the underside of the net’s roof before you could say Martin Tyler.
And that was it. City in control, well over half an hour to go, but game over.
Ferran Torres confirmed as much 83 seconds later.
Now it is over to Liverpool, otherwise a win against Chelsea at the Etihad next Saturday will seal matters. Or failing that, away at Newcastle or Brighton, or at home to Everton.
And you would not bet against Aguero playing a decisive role if City still need a result after the game at Old Trafford on Sunday.
He has struggled during his limited action this season but there were signs in the second half – even apart from his deadlock-breaking boomer – that the sharpness will return.
This is a player who has always needed a run of games after injury to get back into prime condition, physically and mentally.
Aguero turns 33 in early June but there could well be, fitness permitting, two seasons left in him at the elite level.
Where he will end up is unclear but Barcelona might well be favourites to give him a grand, fitting stage on which to play out his career
In the meantime, what a footballer to be able to call on when you want to give a few a rest ahead of a Champions League semi-final second leg.
Remarkably, Raheem Sterling, whose day was summed up when he fired against a post from an Aguero pass, was also in that category.
Sterling is facing a challenge he probably never imagined. It was not that long ago when he seemed pretty indispensable to both club and country.
Now, both Guardiola and Gareth Southgate seem flushed with alternatives.
If Guardiola decides to play without anything resembling a conventional number nine, the preferred front three would appear to be Riyad Mahrez, Kevin de Bruyne and Phil Foden with the next cab off the rank being Bernardo Silva.
Should Raheem Sterling start for Manchester City? Have your say in the comments.
That leaves Sterling in this shadow eleven, clearly somewhere he does not want to be during imminent contract negotiations.
Sterling has two years left on his current deal and club executives might balk at the idea of a bumper pay rise for a player dropping down Guardiola’s rankings.
City cannot just buy, buy, buy and Sterling, unthinkable as it seems, might just be one of those assets they might be willing to sell.
He does make things happen. He is a frequent threat. But the regularity with which he takes wrong decisions in the penalty area seems to be increasing game by game.
At the moment, such has been his value to Southgate, Sterling is probably still favourite to start England’s first game at the Euros.
But if he does not become more clinical in City’s last four Premier League games of the season, Southgate will have a tricky decision to make.
Still, Sterling would walk into any other Premier League team, as would Aguero, probably.
The fact they will be lucky to see any action against PSG on Tuesday is a reflection of the strength of Guardiola’s squad.
No wonder the Premier League title might well be won with four games to spare.
And if it is, at least one of the club’s greatest-ever players can point to this day and say he had a part in it.
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